摘要 |
The sound-insulating construction comprises sound-absorbent material placed or incorporated in an air or gas intake, has a width or depth (B) between 50 and 200 mm and a length (L) or diameter dependent upon the rate of flow. It has a number of holes (3) extending into the material (1) from one side (4) and through the entire width to the other side (5). Each hole is surrounded by the sound-absorbing material with a thickness which is at least equal to the radius of the hole. |